Method for creating and improved image on a photomask by negatively and positively overscanning the boundaries of an image pattern at inside corner locations

ABSTRACT

An method for creating an image on a photosensitive material with enhanced inside corner resolution using a raster scan exposure system. The photosensitive material may comprise a layer of an unexposed photomask. An energy beam scan is extended by one or more addressable locations beyond the boundaries of the desire pattern at inside corner locations in both X and Y axes. Thus, the image formed in the photosensitive material and, in turn, the attenuator material more accurately reflects the desired image as defined in a data file.

BACKGROUND

The present invention relates to a method and apparatus for creatingimages in photosensitive material, and more specifically to a method andapparatus for creating photomasks using a raster scan based exposuresystem in which the image formed in the photosensitive resist materialand, in turn, the attenuator material, has improved definition of insidecorners.

Photomasks are used in the semiconductor industry to transfer microscaleimages defining a semiconductor circuit onto a silicon or galliumarsenide substrate or wafer. The process for transferring the image froma photomask to a silicon substrate or wafer is commonly referred to aslithography or microlithography. Generally, a photomask is comprised ofa substrate and an attenuator. A typical or binary photomask iscomprised of a quartz substrate and a chrome attenuator. The pattern ofthe attenuator material is representative of the image desired to beformed on a silicon wafer. To develop an image on a silicon wafer, alayer of photosensitive material (i.e., photoresist) is applied to asilicon substrate. The photomask is placed between the silicon wafer anda light or other energy source. The light or energy is inhibited frompassing through the areas of the photomask in which the attenuator ispresent. The solubility of the photoresist material is changed in areasexposed to the light or energy. In the case of a positivephotolithographic process, the exposed photoresist becomes soluble andcan be removed. In the case of a negative photolithographic process, theexposed photoresist becomes insoluble and unexposed soluble photoresistis removed.

After the soluble photoresist is removed, the latent image istransferred to the substrate by a process well known in the art which iscommonly referred to as etching. Once the pattern is etched onto thesubstrate material, the remaining resist is removed resulting in afinished product.

The pattern formed in the attenuator material defining the image to betransferred to the silicon substrate is produced by a similar process.The desired image to be created on the photomask is initially defined byan electronic data file typically generated by a computer aided design(CAD) system. The data file is loaded into an exposure system whichscans an electron beam (E-beam) in a raster fashion across an unexposedor blank photomask which, as shown in FIG. 1A, is comprised of a layerof photosensitive material 2, a layer of attenuator material 4, and asubstrate 6.

Examples of raster scan exposure systems are described in U.S. Pat. No.3,900,737 to Collier and U.S. Pat. No. 3,801,792 to Lin. Each finitelocation in which the E-beam can be positioned is referred to as anaddressable location or pixel. Typically, the physical dimensions of anaddressable location, and hence the resolution of the exposure system,are defined by diameter or width of the E-beam. As the E-beam is scannedacross the blank photomask, the exposure system energizes the E-beam ataddressable locations defined by the electronic data file. As shown inFIG. 1B, the unexposed, soluble photoresist is removed and the exposed,insoluble photoresist material 8 remains adhered to the attenuatormaterial 4. As shown in FIG. 1C, the attenuator material which is nolonger covered by the photoresist material is removed by a well knownetching process leaving only portions of attenuator material 10 whichcorrespond to the hardened photoresist material 8. As shown in FIG. 1D,the hardened photoresist material is subsequently removed leaving theattenuator material 10 conforming to the image defined in the data fileremaining on the substrate. The above process is described utilizing apositive photoresist material, however, the same process is applicableif negative photoresist (i.e., the exposed resist becomes soluable) isutilized.

It will be appreciated that the more accurately the attenuator patternreflects the desired image defined in the electronic data file, the moreaccurately the image produced on the silicon substrate will reflect thedesired image. However, the pattern formed in the attenuator material bythe raster scan exposure system is not a perfect reproduction of thedesired image defined by the electronic data file. Factors such as thecircular beam diameter, whether or not an edge is scanned or unscanned,and dose proximity effects all effect the quality of the image formed inthe photosensitive and attenuator materials. As will be describedherein, the degradation in correlation between the desired and createdimages is most pronounced at “inside corners” locations.

The shortcomings of the prior art process are depicted in FIG. 2. InFIG. 2A, images 12 and 14 represent the desired image to be produced ona photomask as defined by the electronic data file. FIG. 2B depicts theraster scanning process of the E-beam with the vertical arrows depictingthe direction of the E-beam scan. When the E-beam 16 is positioned ataddressable locations defining the desired images 12 and 14, the E-beam16 is energized thereby exposing the corresponding portions ofphotosensitive resist material. In practice, the E-beam is notde-energized when passing between addressable locations which are bothintended to be exposed. FIG. 2C depicts the resultant image created inthe photoresist material and hence the attenuator material. As shown inFIG. 2C, the inside corners 18 of the image are rounded and do notaccurately reflect the image defined by the electronic data file, whileoutside corners 20 more closely represent the image defined in the datafile.

FIG. 3 demonstrates the difference in reproducibility of the desiredimage at inside corner and outside corner locations. FIG. 3A is anenlarged depiction of a typical outside corner 20. When E-beam 16reaches the horizontal boundary 22 of the desired image, the beam isde-energized and repositioned for the next scan line. Horizontalboundary 22 is considered an unscanned edge because the E-beam 16 is notpassed along the boundary in an uninterrupted scan. Conversely, verticalboundary 24 is considered a scanned edge because E-beam 16 is passedalong the boundary in an uninterrupted scan. As the beam is scanned inthe scan line directly adjacent to vertical boundary 16, it passesbeyond the horizontal boundary 22 thereby forming a clean or sharpcorner in the photosensitive resist material.

FIG. 3B is an enlarged depiction of a typical inside corner 18. WhenE-beam 16 reaches the horizontal boundary 22 of the desired image, thebeam is de-energized and, as such, horizontal boundary 22 is consideredan unscanned edge. Although vertical boundary 24 is considered a scannededge (i.e., the beam is passed along the boundary in an uninterruptedscan) the beam does not extend past the horizontal boundary 22. It willtherefore be appreciated that an inside corner 18 will be less sharp ormore rounded than an outside corner 20. The deviation from the desiredimage is propagated from the photomask to the silicon substrate therebydegrading the performance or capabilities of the semiconductorcircuitry.

Prior art references have considered the limitations of a raster scanexposure system for use in creating photomasks. For example, U.S. Pat.No. 4,498,010 issued to Biecheler addresses the problem of producingimages in photosensitive material in which the edge of an the image isbetween two rows of addressable locations. To overcome system resolutionincompatibility, every other addressable locations of the scan line thatis beyond the desired image is exposed to the particle beam. Afterexposure, the areas or valleys between the alternately exposedaddressable locations are allegedly filled and the feature width isapproximately one-half a addressable location width.

In the related field of optical proximity correction technology, U.S.Pat. No. 5,663,893 to Wampler describes the use of serifs to moreaccurately produce a desired image on the silicon substrate. Serifs areselective distortions of the features of the attenuator pattern whichimprove the quality of resulting images through the use of well knownmicro-optic principles (e.g., diffraction). The use of serifs aregenerally described with reference to FIG. 4. As shown in FIG. 4A, thedesired image 26 to be created on a silicon substrate is a square. Withreference to FIG. 4B, the desired image to be formed in thephotosensitive resist material includes serifs 28 at each corner, eachserif including inside corners 30 a-30 c. FIG. 4C represents the imagecreated in the photoresist material and attenuator material using theraster scan E-beam process described above. As shown, inside corners 34a-34 c of the serifs 32 are rounded thereby reducing their micro-opticeffects and thus the quality of the image formed on the siliconsubstrate. As will be discussed further herein, the present inventioncan be used in conjunction with serifs to improve the quality of thecreated image.

SUMMARY OF INVENTION

Accordingly, it is the object of the present invention to provide amethod for creating an image in a photosensitive material which moreaccurately reflects the desired image as defined by an electronic datafile.

It is a further object of the present invention to provide a method forcreating photomasks using raster scan exposure systems wherein theimages formed on photomasks produced by the method more accuratelyreflect the desired image as defined in an electronic data file.

It is a further object of the present invention to provide a method forcreating semiconductor wafers using raster scan exposure systems whereinthe images formed on the wafers produced by the method more accuratelyreflect the desired image as defined in an electronic data file.

It is still a further object of the present invention to provide araster scan exposure system which produces images in photosensitivematerials which more accurately reflects the desired image to beproduced as defined by an electronic data file.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A-1D illustrate the process for creating an image on a photomask.

FIGS. 2A-2C illustrate the prior art process for creating images inphotosensitive material using a raster scan exposure systems.

FIGS. 3A-3B illustrate how inside and outside corners of an image isformed in a photosensitive material by the prior art raster scanexposure systems.

FIGS. 4A-4C illustrate one type of optical proximity correctiontechnology known as serifs.

FIGS. 4D-4E illustrate the addition of the present invention to serifsand the resulting improved serif inside corner definition.

FIG. 5 illustrates how inside corners of an image are formed in aphotosensitive material by the method of the present invention.

FIG. 6 describes the process used in the present invention to modify thedata file of the desired image.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

To correct the shortcomings of the prior art with respect to the imagingof inside corners as described above, the present invention extends theE-beam scan by a one or more addressable locations or pixel at each, orselected, inside corners. In accordance with the preferred embodiment ofthe present invention the, E-beam is overscanned in the direction of thebeam scan as well as the direction perpendicular to the beam scan. Inother words, addressable locations adjacent to an inside corner locationin both the X and Y axes are both exposed to the energized E-beam.

With reference to FIG. 5A, the E-beam 16 is scanned in the directionperpendicular to horizontal edge 22, and as shown, the E-beam scan isgenerally terminated at addressable locations defined by the horizontaledge or boundary 22. However, in accordance with the present invention,when the E-beam is scanned in the scan line adjacent to vertical edge orboundary 24, the scan is extended into addressable location 40 which isbeyond the horizontal boundary 22. Additionally, in accordance with thepresent invention, the beam is scanned in a scan line adjacent to, butoutside vertical boundary 24. However, the beam is only energized in theaddressable location 42 which is also adjacent to horizontal boundary22. Thus, it will be appreciated that in the above described preferredembodiment, the scan extension is in both horizontal (X axis) andvertical (Y axis) directions.

Depending on the size of the E-beam diameter, the scan of the beam maybe extended more than one addressable location in both the horizontaland vertical directions. FIG. 5B shows an embodiment of the presentinvention in which the E-beam is overscanned by two addressablelocations in both the horizontal and vertical directions because of thereduced beam diameter. With reference to FIG. 5B, E-beam 16 is scannedin the direction perpendicular to horizontal edge 22 with the scan beingterminated at addressable locations defined by horizontal edge 22.However, in accordance with the present invention, when the E-beam isscanned in the two scan lines closest to vertical boundary 24, the scanis extended into addressable locations 44, 46, 48, and 50 respectivelywhich are beyond the horizontal boundary 22. Additionally, the beam isscanned in the two scan lines closest to, but outside vertical boundary24. However, the beam is only energized in the addressable locations 52,54, 56, and 58 which are adjacent to horizontal boundary 22.

As indicated above, the present invention can be utilized in conjunctionwith the optical proximity correction known as serifs. FIG. 4Cillustrates the pattern formed in the photosensitive resist wherein thedesired image includes serifs 32 at each corner. As shown, the insidecorners of the serifs 34 a-34 c are rounded and not as sharp as corners30 a-30 c defined in the electronic data file illustrated by FIG. 4C.FIG. 4D depicts the data file of FIG. 4C modified to include overscan ateach inside corner location in both the horizontal and verticaldirections depicted by references 36 b and 36 a. FIG. 4E illustrates thepattern formed in the photosensitive resist based on the modifiedpattern data. As shown, the inside corners 38 a-38 c of the image formedin the photoresist material using the overscan technique of the presentinvention more accurately reflect the desired image defined by theelectronic data file shown in FIG. 4B.

Although the above embodiments of the present invention discuss theamount of overscan to be the same in both the horizontal and verticaldirections, such need not be the case. The amount of overscan in eachdirection can be asymmetric and take into account factors such as beamshape. Additionally, although the above descriptions of the E-beampositioning discuss the scanning of the beam in a vertical direction, itwill be appreciated that the present invention can be practicedindependent of the direction of scan so long as the photoresist materialis exposed at the appropriate addressable locations.

FIG. 6 describes the process for modifying the original electronic datafile using standard boolean operations. In each of the figures theoriginal pattern is shown by vertical boundary 60 and horizontalboundary 62FIG. 6A illustrates the original data file defining the imagedesired to be formed in the photosensitive resist material. Inaccordance with the present invention, the original pattern is sizedpositively in the X-axis only by the desired amount of overscan togenerate the intermediate pattern shown in FIG. 6B. The intermediatepattern of FIG. 6B is next sized positively in the Y-axis only by thedesired amount of overscan to generate the intermediate pattern shown inFIG. 6C. The intermediate pattern of FIG. 6C is next sized negatively inthe Y-axis only by the desired amount of overscan to generate theintermediate pattern shown in FIG. 6D. The original pattern data is nextsized negatively in the X-axis only by the desired amount of overscan togenerate the intermediate pattern shown in FIG. 6E. The intermediatepatterns shown in FIGS. 6B and 6C are then “OR'ed” to generate theintermediate pattern shown in FIG. 6F. Next, the intermediate patternsshown in FIGS. 6D and 6E are then “OR'ed” to generate the intermediatepattern shown in FIG. 6G. The intermediate patterns shown in FIGS. 6Fand 6G are then “OR'ed” to generate the 15 intermediate pattern shown inFIG. 6H. Finally, the original pattern shown in FIG. 6A is “OR'ed” withthe intermediate pattern shown in FIG. 6H to generate the final patternshown in FIG. 6I which contains the desired amount of scan extensionslocated at the inside corners.

Although FIGS. 6A-6I describe a method for modifying a data filecomprising s rectangular shape, those skilled in the art will appreciatethat the above described method is also applicable to more compleximages such as image 14 of FIG. 2A. Additionally, those skilled in theart will appreciate that by comparing the modified file shown in FIG. 6Ito the original file shown in FIG. 6A, the location of inside cornerscan be assertained.

The scan extension technique for inside corners of the present inventioncan be realized in a number of ways. The first way in which the scanextension can be realized is by including the desired amount of scanextension in both horizontal and/or vertical directions in the originaldata file defining the desired image to be formed in the photosensitiveresist material. The data file can be loaded into the lithographicexposure system without further processing.

The second way in which the scan extension can be realized is bymodifying an electronic data file adding desired amount of scanextension in both horizontal and/or vertical directions before the datais loaded into the lithographic exposure system. Such a modificationcould be carried out by the computer aided design system in which theoriginal data file was created by performing the steps illustrated inFIG. 6. Alternatively, the modification could be performed by a separatecomputer based system which is capable of accepting and reading theoriginal data file in the format and on the media created by thecomputer aided design system. After reading and modifying the originaldata file, the computer based system would write the modified data fileto a media, which may include the media on which the original data filewas stored, which is compatible with the lithographic exposure system.One advantage of this implementation is that the lithographic exposuresystem does not need to be modified. However, one drawback is that thescan extension modification process needs to be performed on each datafile which would add a constant recurring cost to the production of eachphotomask.

A third way in which the scan extension method of the present inventioncan be realized is by modifying the lithographic exposure system suchthat the scan extension technique of the present invention is performedautomatically during the exposure process using the original data file.While such a modification would result in a one time non-recurring cost,there would be no recurring costs for the production of each individualphotomask.

Various additional modifications and improvements thereon will becomereadily apparent in those skilled in the art. For example, the presentinvention can be utilized in exposure systems utilizing energy beamsother than E-beams such as lasers, ion beams, or x-rays. Furthermore, asemiconductor wafer can be directly created by exposing thephotosensistive material on the unexposed wafer to a raster scannedE-beam in accordance with the method of the present invention.

Accordingly, the spirit and scope of the present invention is to beconstrued broadly and limited only by the appended claims, and not bythe foregoing specification.

What is claimed is:
 1. A method for creating an image in aphotosensitive material utilizing a raster scan exposure systemcomprising the steps of: (a) creating an initial data file comprisinginformation defining the desired image to be produced in saidphotosensitive material, (b) determining the amount of overscan forinside corner locations of said initial data file, (c) creating a firstset of intermediate data patterns by positively sizing said data file inhorizontal and vertical directions by said determined amount ofoverscan, (d) creating a second set of intermediate data patterns bynegatively sizing said first set of intermediate data patterns inhorizontal and vertical directions by said determined amount ofoverscan, (e) performing boolean operations on said first and second setof intermediate data patterns and said initial data file to generate amodified data file having said determined amount of overscan at insidecorner locations, and (f) scanning a beam of radiation generated by saidexposure system across the photosensitive material in accordance withsaid modified data file.
 2. The method for generating an image in aphotosensitive material according to claim 1 wherein said data file foruse by said exposure system is generated by a computer aided designsystem.
 3. The method for generating an image in a photosensitivematerial according to claim 1 wherein determination of the amount ofoverscan for each of said inside corner locations is a function of saidexposure system's radiation beam dimensions.
 4. The method forgenerating an image in a photosensitive material according to claim 1wherein the amount of desired overscan is different for the horizontaland vertical directions.
 5. The method for generating an image in aphotosensitive material according to claim 1 wherein said radiation beamof said exposure system is an E-Beam.
 6. The method for generating animage in a photosensitive material according to claim 1 wherein saidradiation beam of said scan exposure system is X-ray.
 7. The method forgenerating an image in a photosensitive material according to claim 1wherein said radiation beam of said exposure system is a Laser.
 8. Themethod for generating an image in a photosensitive material according toclaim 1 wherein said radiation beam of said exposure system is an ionbeam.
 9. The method for generating an image in a photosensitive materialaccording to claim 1 wherein said photosensitive material comprises alayer of an unexposed photomask.
 10. The method for generating an imagein a photosensitive material according to claim 1 wherein saidphotosensitive material comprises a layer of an unexposed semiconductorwafer.
 11. A method for making a photomask comprising the steps of: (a)creating an initial data file comprising information defining thedesired image to be produced on an unexposed photomask, (b) determiningthe amount of overscan for inside corner locations of said initial datafile, (c) creating a first set of intermediate data patterns bypositively sizing said data file in horizontal and vertical directionsby said determined amount of overscan, (d) creating a second set ofintermediate data patterns by negatively sizing said first set ofintermediate data patterns in horizontal and vertical directions by saiddetermined amount of overscan, (e) performing boolean operations on saidfirst and second set of intermediate data patterns and said initial datafile to generate a modified data file having said determined amount ofoverscan at inside corner locations, and (f) loading said modified datafile into a raster scan exposure system, said exposure system utilizingsaid modified data file to expose portions of said unexposed photomaskto a beam of radiation, said exposed portions of said unexposedphotomask conforming to the desired pattern of attenuator material onsaid photomask.
 12. The method for generating a photomask according toclaim 11 wherein said data file for use by said exposure system isgenerated by a computer aided design system.
 13. The method forgenerating a photomask according to claim 11 wherein said determinationof an amount of desired overscan for each of said inside cornerlocations is a function of the dimensions of said radiation beam. 14.The method for generating a photomask according to claim 11 wherein theamount of desired overscan is different in the horizontal and verticaldirections.
 15. The method for generating a photomask according to claim11 wherein said radiation beam is an E-beam.
 16. The method forgenerating a photomask according to claim 11 wherein said radiation beamis an X-ray.
 17. The method for generating a photomask according toclaim 11 wherein said radiation beam is a Laser.
 18. The method forgenerating a photomask according to claim 11 wherein said radiation beamis an ion beam.
 19. The method for generating a photomask according toclaim 11 wherein said photomask is comprised of glass substrate and achrome attenuator.
 20. The method for generating a photomask accordingto claim 11 wherein said photomask is comprised of a glass substrate anda MoSiON attenuator.
 21. A method for producing a semiconductor wafercomprising the steps of: (a) creating an initial data file comprisinginformation defining the desired image to be produced on an unexposedsemiconductor wafer, (b) determining the amount of overscan for insidecorner locations of said initial data file, (c) creating a first set ofintermediate data patterns by positively sizing said data file inhorizontal and vertical directions by said determined amount ofoverscan, (d) creating a second set of intermediate data patterns bynegatively sizing said first set of intermediate data patterns inhorizontal and vertical directions by said determined amount ofoverscan, (e) performing boolean operations on said first and second setof intermediate data patterns and said initial data file to generate amodified data file having said determined amount of overscan at insidecorner locations, and (f) loading said modified data file into a rasterscan exposure system, said exposure system utilizing said modified datafile to expose portions of said unexposed semiconductor wafer to a beamof radiation, said exposed portions of said semiconductor waferconforming to the desired pattern to be produced on said semiconductorwafer.
 22. The method for generating a semiconductor wafer according toclaim 21 wherein said data file for use by said exposure system isgenerated by a computer aided design system.
 23. The method forgenerating a semiconductor wafer according to claim 21 whereindetermination of an amount of overscan for each of said inside cornerlocations is a function of the dimensions of said radiation beam. 24.The method for generating a semiconductor wafer according to claim 21wherein an amount of desired overscan in both the horizontal andvertical directions is determined for each of said inside cornerlocations.
 25. The method for generating a semiconductor wafer accordingto claim 21 wherein said radiation beam is an E-beam.
 26. The method forgenerating a semiconductor wafer according to claim 21 wherein saidradiation beam is an X-ray.
 27. The method for generating asemiconductor wafer according to claim 21 wherein said radiation beam isan ion beam.
 28. The method for generating a semiconductor waferaccording to claim 21 wherein said radiation beam is a Laser.
 29. Amethod for producing an image in a photosensitive material utilizing araster scan exposure system comprising the steps of: (a) creating a datafile comprising information defining the desired image to be produced onsaid photosensistive material, (b) loading said data file into saidexposure system, said exposure system: (1) creating an initial data filecomprising information defining the desired image to be produced in saidphotosensitive material, (2) determining the amount of overscan forinside corner locations of said initial data file, (3) creating a firstset of intermediate data patterns by positively sizing said data file inhorizontal and vertical directions by said determined amount ofoverscan, (4) creating a second set of intermediate data patterns bynegatively sizing said first set of intermediate data patterns inhorizontal and vertical directions by said determined amount ofoverscan, (5) performing boolean operations on said first and second setof intermediate data patterns and said initial data file to generate amodified data file having said determined amount of overscan at insidecorner locations, and (6) scanning a beam of radiation generated by saidexposure system across said photosensitive material in accordance withsaid modified data file.
 30. The method for generating an image in aphotosensitive material according to claim 29 wherein said data file foruse by said exposure system is generated by a computer aided designsystem.
 31. The method for generating an image in a photosensitivematerial according to claim 29 wherein said photosensitive materialcomprises a layer of an unexposed photomask.
 32. The method forgenerating an image in a photosensitive material according to claim 29wherein said photosensitive material comprises a layer of an unexposedsemiconductor wafer.
 33. The method for generating an image in aphotosensitive material according to claim 29 wherein determination ofthe amount of overscan for each of said inside corner locations is afunction of the dimensions of said radiation beam.
 34. The method forgenerating an image in a photosensitive material according to claim 29wherein an amount of desired overscan in both the horizontal andvertical directions is determined for each of said inside cornerlocations.
 35. The method for generating an image in a photosensitivematerial according to claim 29 wherein said radiation beam is an E-Beam.36. The method for generating an image in a photosensitive materialaccording to claim 29 wherein said radiation beam is an X-ray.
 37. Themethod for generating an image in a photosensitive material according toclaim 29 wherein said radiation beam is an ion beam.
 38. The method forgenerating an image in a photosensitive material according to claim 29wherein said radiation beam is a Laser.
 39. A method for creating animage in a photosensitive material comprising the steps of: (a) creatinga data file for use by a raster scan exposure system, said data filecomprising information defining the desired image to be produced in saidphotosensitive material, (b) determining the location of inside cornersof said desired image based on said data file, (c) determining theamount of overscan for each of said inside corner locations, and (d)scanning a beam of radiation produced by said exposure system across thephotosensitive material in accordance with said information in said datafile, wherein said determined amount of overscan is overscanned beyondboundaries of said inside corner locations.
 40. The method forgenerating an image in a photosensitive material according to claim 39wherein said data file for use by said exposure system is generated by acomputer aided design system.
 41. The method for generating an image ina photosensitive material according to claim 39 wherein determination ofthe amount of overscan for each of said inside corner locations is afunction of said exposure system's radiation beam dimensions.
 42. Themethod for generating an image in a photosensitive material according toclaim 39 wherein the amount of desired overscan is different for thehorizontal and vertical directions.
 43. The method for generating animage in a photosensitive material according to claim 39 wherein saidradiation beam of said exposure system is an E-Beam.
 44. The method forgenerating an image in a photosensitive material according to claim 39wherein said radiation beam of said scan exposure system is X-ray. 45.The method for generating an image in a photosensitive materialaccording to claim 39 wherein said radiation beam of said exposuresystem is a Laser.
 46. The method for generating an image in aphotosensitive material according to claim 39 wherein said radiationbeam of said exposure system is an ion beam.
 47. The method forgenerating an image in a photosensitive material according to claim 39wherein said photosensitive material comprises a layer of an unexposedphotomask.
 48. The method for generating an image in a photosensitivematerial according to claim 39 wherein said photosensitive materialcomprises a layer of an unexposed semiconductor wafer.